I haven't posted here for years!
What's your room humidity .. looks like a tight space .. I'm guessing that the plant's cannot transpire water quick enough from the leaves .. I've had similar looking plants in the past, most often in confined spaces .. what's your air flow like? would be great if you had an RH meter and was able to monitor the humidity in that space . is the air thick with water when you stick your head in? i.e is there a noticeable difference between the thinness of the air in another room compared to the heavy air in your grow space? .. My leaves took on that appearance the most when I ran hydro/nft in a 2mx1.5mx1.5m box .. It's ok in veg but might give you problems in bloom; problems such as mould ..
like i say, I haven't posted here for a long while and haven't grown anything for around 24 months now .. I'm hoping someone can verify my comment